1862.] MR. J. Y. JOHNSON ON ALEPISAURUS FEROX. 127 



but the pectoral fin has fourteen in place of fifteen rays, the ventral 

 fin ten in place of nine rays, and the anal fin sixteen in place of 

 seventeen rays. The first ray of the pectoi'al fin in the fish examined 

 by Mr. Bennett was the longest. In this specimen the fifth and 

 sixth rays are the longest (being 7\ inches long), and they are rather 

 more than twice the length of the strongly-serrated first ray, which 

 is superior in length only to the three last. The first dorsal fin 

 (the base of which is 32 inches long) arises out of a groove, each 

 margin of which consists of a loose fold of adipose skin. The first 

 ray is jointed above, and is strongly serrate along its free edge, like 

 the first rays of the pectorals and ventrals. The first fifteen or six- 

 teen rays appear to be simple, the others sparingly branched ; but 

 the only perfect ray in my specimen is the fourth, and that is 

 12 inches long. The first ray of the ventral fin, though simple and 

 strong below, is jointed above and ends in a weak point. The first 

 two rays of the anal fin are short, the succeeding four long, and the 

 remaining rays short. The anterior part of this fin is fleshy, and at 

 the base of this part there is a groove on each side. The length of 

 the base of the whole fin, compared with the total length of the fish, 

 is as 1 to 1 1^, instead of as 1 to 10 in Mr. Bennett's example. The 

 caudal fin measures 7\ inches in length, and the tips of the lobes 

 are 9 inches asunder. 



Along the middle of each side on the posterior half of the body 

 there is a low adipose keel of a black colour ; and this marks the 

 course, at this part, of the lateral line, which is unarmed throughout. 

 The fish is covered with a thin smooth skin, and is entirely destitute 

 of scales. 



As to the dentition, there^are at each side of the mandible, be- 

 ginning at the posterior end, ten teeth of moderate size, directed 

 backwards, and flattened, triangular, and pointed. Then come three 

 long-pointed teeth, which decrease in length forwards ; then five 

 subulate teeth, having before them two long teeth on one side of the 

 mandible, on the other only one ; lastly, at the tip, one acicular tooth. 

 The weak slender premaxillary is set with a single row of small sharp 

 triangular teeth, about eighty- five on each side. The palatine bones 

 are set posteriorly with a row of larger teeth, which, being flat, sharp, 

 and triangular, resemble the teeth of a saw. They are directed back- 

 wards, and correspond in size and shape with the opposite teeth of 

 the mandible. At the anterior part of each palatine bone is a row 

 of seven or eight long formidable teeth, the hinder ones being larger; 

 they are flattened, dagger-like, and are directed backwards. Behind 

 these on one side are two long teeth, but only one such tooth on the 

 other. The vomer is toothless. 



"With reference to the figure accompanying Mr. Bennett's descrip- 

 tion, it may be remarked that the nostrils are wrongly indicated, 

 being much posterior to the place at which they are represented to 

 be. They are really situated a little nearer the eyes than the snout. 

 The two orifices of each pair, being small and close together, may have 

 been overlooked ; and a couple of slight depressions with a bony 

 tubercle, in advance of their true position, have been apparently mis- 



